Hi - it doesn't matter as far as bedpostx and probtrackx are concerned. Cheers Saad On 29 Mar 2013, at 22:33, Ran Xu wrote: > Dear FSL experts, > > I used [0,0,0] as the origin of nodif_brain.nii and this was used in the bedpostx. Now, I need to change the origin of nodif_brain.nii to the center of this image. Will this change affect the obtained parameters of bedpostx, e.g. "merged_f1samples.nii"? I mean, all the "merged.*" files calculate fibers according to this new origin in the probtrackx2? I am not sure if these "merged" files can automatically determine the coordinate space according to the input, e.g."nodif_brain_mask". > > Thanks. > > Ran -- Saad Jbabdi University of Oxford, FMRIB Centre JR Hospital, Headington, OX3 9DU, UK (+44)1865-222466 (fax 717) www.ndcn.ox.ac.uk/team/researchers/saad-jbabdi